Optical sensors including a light-impeding pattern

ABSTRACT

Optical sensors including a light-impeding pattern are provided. The optical sensors may include a plurality of photoelectric conversion regions, a plurality of lenses on the plurality of photoelectric conversion regions, and a light-impeding layer extending between the plurality of photoelectric conversion regions and the plurality of lenses. The light-impeding layer may include an opening between a first one of the plurality of photoelectric conversion regions and a first one of the plurality of lenses. The optical sensors may be configured to be assembled with a display panel such that the plurality of lenses are disposed between the light-impeding layer and the display panel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This U.S. non-provisional patent application is a continuation of U.S.patent application Ser. No. 15/954,818, filed Apr. 17, 2018, whichclaims priority under 35 U.S.C. § 119 to Korean Patent Application No.10-2017-0049219, filed on Apr. 17, 2017, in the Korean IntellectualProperty Office, the disclosure of which is hereby incorporated byreference herein in its entirety.

BACKGROUND

The present disclosure relates to the field of electronics and, moreparticularly, to optical sensors.

An optical sensor is a semiconductor device that converts optical imagesinto electrical signals. As the computer and communications industrieshave developed, demand has increased for high-performance opticalsensors in a variety of applications, including digital cameras,camcorders, personal communication systems, gaming machines, securitycameras, micro-cameras for medical applications, and/or robots.Accordingly, there is an increased demand for high-performance imagingdevices or high-performance optical sensors.

One problem for optical sensors, however, is image blur. For example,image blur may occur when an optical sensor is close to an object thatis to be imaged. As a result, the quality of images that are taken inclose proximity to an object may be undesirably low.

SUMMARY

Some embodiments of the inventive concepts provide an optical sensorincluding a pixel structure, which is configured to selectively collectlight to be incident at a desired incident angle.

Some embodiments of the inventive concepts provide an optical sensorwhich is used to easily take an image of a near object.

According to some embodiments of the inventive concepts, an image sensormay include a substrate including a plurality of pixels, a deviceisolation pattern provided on borders between the plurality of pixels,the device isolation pattern penetrating at least a portion of thesubstrate and having a first width between an adjacent pair of thepixels, micro lenses provided on a surface of the substrate, and a gridpattern provided between the substrate and an array of the micro lensesand overlapped with the plurality of pixels and the device isolationpattern. The grid pattern may include a plurality of openingspenetrating the same, and each of the plurality of openings may beoverlapped with a corresponding one of the plurality of pixels, whenviewed in a plan view parallel to the surface of the substrate. The gridpattern may have a second width which corresponds to a distance betweenan adjacent pair of the plurality of openings and is larger than thefirst width.

According to some embodiments of the inventive concepts, an image sensormay include a substrate including at least a pair of pixels, a deviceisolation pattern provided on a border between the pair of the pixels topenetrate at least a portion of the substrate, and a grid patternprovided on a surface of the substrate and overlapped with the deviceisolation pattern when viewed in a plan view parallel to the surface ofthe substrate. The device isolation pattern may have a first width thatis smaller a second width of the grid pattern, and the first width andthe second width may be distances measured in a direction parallel tothe surface of the substrate. According to some embodiments of theinventive concepts, an image sensor may include a substrate including aplurality of pixels, a device isolation pattern provided on bordersbetween the plurality of pixels, the device isolation patternpenetrating at least a portion of the substrate and having a first widthbetween an adjacent pair of the plurality of pixels, micro lensesprovided on the plurality of pixels, respectively, the micro lensesbeing connected to each other by a flat portion provided therebetween,and a grid pattern provided between the substrate and an array of themicro lenses, the grid pattern including a plurality of openings whichare provided to penetrate the same and are vertically overlapped withthe plurality of pixels, respectively. The grid pattern may have asecond width corresponding to a distance between an adjacent pair of theplurality of openings, the flat portion may have a third widthcorresponding to a distance between an adjacent pair of the microlenses, and the third width may be greater than the first width and maybe smaller than the second width.

According to some embodiments of the inventive concepts, an opticalsensor of an optical scanner may include a plurality of photoelectricconversion regions, a plurality of lenses on the plurality ofphotoelectric conversion regions, and a light-impeding layer extendingbetween the plurality of photoelectric conversion regions and theplurality of lenses. The light-impeding layer may include an openingbetween a first one of the plurality of photoelectric conversion regionsand a first one of the plurality of lenses. The optical sensor may beconfigured to be assembled with a display panel such that the pluralityof lenses are disposed between the light-impeding layer and the displaypanel.

According to some embodiments of the inventive concepts, an opticalsensor of an optical scanner may include a plurality of photoelectricconversion regions, a plurality of lenses on the plurality ofphotoelectric conversion regions, which are arranged along a firstdirection, and a light-impeding layer extending between the plurality ofphotoelectric conversion regions and the plurality of lenses. Thelight-impeding layer may include an opening between a first one of theplurality of photoelectric conversion regions and a first one of theplurality of lenses. A ratio of a widest width of the opening in thefirst direction to a widest width of the first one of the plurality oflenses in the first direction may be at least about 1:2.

According to some embodiments of the inventive concepts, an opticalsensor of an optical scanner may include a plurality of photoelectricconversion regions, a plurality of lenses on the plurality ofphotoelectric conversion regions, and a light-impeding layer extendingbetween the plurality of photoelectric conversion regions and theplurality of lenses. The light-impeding layer may include an openingbetween a first one of the plurality of photoelectric conversion regionsand a first one of the plurality of lenses. The light-impeding layer maybe configured to reflect or absorb light incident on the light-impedinglayer such that the light is selectively incident on the first one ofthe plurality of photoelectric conversion regions through the opening. Amagnitude of a first signal generated by the first one of the pluralityof photoelectric conversion regions in response to a first portion ofthe light, which is incident at a substantially right angle on the firstone of the plurality of photoelectric conversion regions, may be abouttwice a magnitude of a second signal generated by the first one of theplurality of photoelectric conversion regions in response to a secondportion of the light, which has an angle relative to the first portionof the light of about 2.5 degrees.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will be more clearly understood from the followingdescription taken in conjunction with the accompanying drawings. Theaccompanying drawings represent non-limiting, example embodiments asdescribed herein.

FIG. 1 is a circuit diagram of a pixel of an image sensor according tosome embodiments of the inventive concepts.

FIG. 2 is a plan view of an image sensor according to some embodimentsof the inventive concepts.

FIG. 3 is a sectional view taken along the line I-I′ of FIG. 2.

FIG. 4 is a sectional view, which is taken along a line corresponding tothe line I-I′ of FIG. 2 and illustrates a modified example of an imagesensor according to some embodiments of the inventive concepts.

FIG. 5 is a sectional view, which is taken along a line corresponding tothe line I-I′ of FIG. 2 and illustrates another modified example of animage sensor according to some embodiments of the inventive concepts.

FIG. 6 is a plan view of an image sensor according to some embodimentsof the inventive concepts.

FIG. 7 is a sectional view taken along the line I-I′ of FIG. 6.

FIG. 8 is a plan view of an image sensor according to some embodimentsof the inventive concepts.

FIG. 9 is a sectional view taken along the line I-I′ of FIG. 8.

FIG. 10 is a plan view of an image sensor according to some embodimentsof the inventive concepts.

FIG. 11 is a sectional view taken along the line I-I′ of FIG. 10.

FIG. 12A is a graph showing an angular response of an image sensoraccording to some embodiments of the inventive concepts.

FIG. 12B is a graph showing an angular response of an image sensoraccording to some embodiments of the inventive concepts.

FIGS. 13A and 13B are sectional views of the portion A of FIG. 3according to some embodiments of the inventive concepts.

FIGS. 14A to 14C are sectional views, which are taken along a linecorresponding to the line I-I′ of FIG. 2 to illustrate a method offorming a grid pattern of an image sensor according to some embodimentsof the inventive concepts.

FIGS. 15A and 15B are sectional views, which are taken along a linecorresponding to the line I-I′ of FIG. 2 to illustrate a method offabricating an image sensor according to some embodiments of theinventive concepts.

FIG. 16 is a schematic diagram of an electronic device including animage sensor according to some embodiments of the inventive concepts.

FIG. 17 is a sectional view taken along the line I-I′ of FIG. 16.

It should be noted that these figures are intended to illustrate thegeneral characteristics of methods, devices, and/or materials utilizedin example embodiments and to supplement the written descriptionprovided below. These drawings are not, however, to scale and may notprecisely reflect the precise structural or performance characteristicsof any given embodiment, and should not be interpreted as defining orlimiting the range of values or properties encompassed by exampleembodiments. For example, the relative thicknesses and positioning oflayers, regions and/or structural elements may be reduced or exaggeratedfor clarity. The use of similar or identical reference numbers in thevarious drawings is intended to indicate the presence of a similar oridentical element or feature.

DETAILED DESCRIPTION

Example embodiments of the inventive concepts will now be described morefully with reference to the accompanying drawings, in which exampleembodiments are shown. As used herein the term “and/or” includes any andall combinations of one or more of the associated listed items. It willbe understood that an optical sensor may also be referred to herein asan “image sensor” (e.g., CMOS image sensor), and an optical sensor maybe included in an optical scanner (e.g., a fingerprint scanner).

FIG. 1 is a circuit diagram of a pixel of an image sensor according tosome embodiments of the inventive concepts.

Referring to FIG. 1, an image sensor may include a plurality of pixelsPX, each of which include a photoelectric conversion region PD, atransfer transistor Tx, a source follower transistor Sx, a resettransistor Rx, and a selection transistor Ax. The transfer transistorTx, the source follower transistor Sx, the reset transistor Rx, and theselection transistor Ax may include a transfer gate TG, a sourcefollower gate SG, a reset gate RG, and a selection gate AG,respectively.

The photoelectric conversion region PD may be, for example, a photodiodeincluding an n-type impurity region and a p-type impurity region. Afloating diffusion region FD may serve as a drain electrode of thetransfer transistor Tx. The floating diffusion region FD may serve as asource electrode of the reset transistor Rx. The floating diffusionregion FD may be electrically connected to the source follower gate SGof the source follower transistor Sx. The source follower transistor Sxmay be connected to the selection transistor Ax.

Hereinafter, an operation of an image sensor according to someembodiments of the inventive concepts will be described with referenceto FIG. 1. Firstly, in order to discharge electric charges from thefloating diffusion region FD in a light-blocking state, a power voltageV_(DD) may be applied to drain electrodes of the reset and sourcefollower transistors Rx and Sx, and the reset transistor Rx may beturned on. Thereafter, if the reset transistor Rx is turned-off and anexternal light is incident into the photoelectric conversion region PD,electron-hole pairs may be generated in the photoelectric conversionregion PD. Holes may be moved toward and accumulated in the p-typeimpurity region of the photoelectric conversion region PD, and electronsmay be moved toward and accumulated in the n-type impurity region of thephotoelectric conversion region PD. If the transfer transistor Tx isturned on, the electric charges (i.e., electrons and holes) may betransferred to and accumulated in the floating diffusion region FD. Achange in amount of the accumulated electric charges may lead to achange in gate bias of the source follower transistor Sx, and this maylead to a change in source potential of the source follower transistorSx. Accordingly, if the selection transistor Ax is turned on, an amountof the electric charges may be read out as a signal (e.g., Vout) to betransmitted through a column line. Signals (e.g., Vout) output from thepixels PX are processed to generate an image of an object that is to beimaged.

Although the pixel of FIG. 1 is illustrated to have a singlephotoelectric conversion region PD and four transistors (i.e., Tx Rx,Ax, and Sx), the inventive concepts are not limited thereto. Forexample, the image sensor may include a plurality of pixels PX, and insome embodiments, the reset transistor Rx, the source followertransistor Sx, or the selection transistor Ax may be shared by adjacentones of the pixels PX. This may make it possible to increase anintegration density of the image sensor.

FIG. 2 is a plan view of an image sensor according to some embodimentsof the inventive concepts, and FIG. 3 is a sectional view taken alongthe line I-I′ of FIG. 2.

Referring to FIGS. 2 and 3, a substrate 100 including a plurality ofpixels PX may be provided. A device isolation pattern 102 may beprovided in the substrate 100, and here, the device isolation pattern102 may be provided along borders between (e.g., border regions of) thepixels PX and may penetrate at least a portion of the substrate 100. Thesubstrate 100 may be, for example, a semiconductor substrate (e.g., asilicon wafer, a germanium wafer, a silicon-germanium wafer, a II-VIcompound semiconductor wafer, or a III-V compound semiconductor wafer)or a silicon-on-insulator (SOI) wafer. The device isolation pattern 102may have a top surface that is coplanar with, or adjacent to, a firstsurface 100 a of the substrate 100. The device isolation pattern 102 mayhave a bottom surface that is coplanar with, or adjacent to, a secondsurface 100 b of the substrate 100. The first and second surfaces 100 aand 100 b may be two opposing surfaces of the substrate 100 spaced apartfrom each other in a first direction D1 that is normal (i.e.,perpendicular) to the first surface 100 a. In some embodiments, all ofthe plurality of pixels PX (i.e., nine pixels) of FIG. 2 output signalsthat are processed to generate an image of an object that is to beimaged.

A photoelectric conversion region PD may be provided in each of thepixels PX. The photoelectric conversion region PD may be an impurityregion that is doped to have a first conductivity type. For example, thephotoelectric conversion region PD may contain n-type impurities (e.g.,phosphorus, arsenic, bismuth, and/or antimony). A well region 104 may beprovided in each of the pixels PX. The well region 104 may be animpurity region that is doped to have a second conductivity typedifferent from the first conductivity type. For example, the well region104 may contain p-type impurities (e.g., aluminum (Al), boron (B),indium (In) and/or gallium (Ga)). The well region 104 may be providedadjacent to the second surface 100 b of the substrate 100, and thephotoelectric conversion region PD may be spaced apart from the secondsurface 100 b of the substrate 100 with the well region 104 interposedtherebetween. A floating diffusion region FD may be provided in each ofthe pixels PX. The floating diffusion region FD may be provided adjacentto the second surface 100 b of the substrate 100. The floating diffusionregion FD may be provided in the well region 104 and may be an impurityregion whose conductivity type is different from that of the well region104. For example, the floating diffusion region FD may be an impurityregion having the first conductivity type (e.g., containing n-typeimpurities).

Transfer gates TG may be provided on the second surface 100 b of thesubstrate 100. The transfer gates TG may be provided on the plurality ofpixels PX, respectively. Each of the transfer gates TG may be providedadjacent to the floating diffusion region FD of a corresponding one ofthe pixels PX.

An interconnection structure 110 may be provided on the second surface100 b of the substrate 100. The interconnection structure 110 mayinclude a first interlayer insulating layer 110 a, a second interlayerinsulating layer 110 b, and a third interlayer insulating layer 110 cwhich are sequentially stacked on the second surface 100 b of thesubstrate 100. The first interlayer insulating layer 110 a may beprovided to be in contact with the second surface 100 b of the substrate100 and to extend on (e.g., cover) the transfer gates TG. Theinterconnection structure 110 may further include via plugs 112, whichare provided to penetrate the first interlayer insulating layer 110 a,and interconnection lines 114, which are provided in the second andthird interlayer insulating layers 110 b and 110 c. Each of the viaplugs 112 may be connected to the floating diffusion region FD of acorresponding one of the pixels PX and may be connected to acorresponding one of the interconnection lines 114.

An anti-reflection layer 120 may be provided on the first surface 100 aof the substrate 100. The anti-reflection layer 120 may be spaced apartfrom the interconnection structure 110 with the substrate 100 interposedtherebetween. The anti-reflection layer 120 may be provided to extend on(e.g., cover) the plurality of pixels PX and the device isolationpattern 102. The anti-reflection layer 120 may impede/prevent light Lfrom being reflected by the first surface 100 a of the substrate 100,thereby allowing the light L to be effectively incident into thephotoelectric conversion region PD. The anti-reflection layer 120 willbe described in more detail with reference to FIGS. 13A and 13B.

A grid pattern 130 may be provided on the first surface 100 a of thesubstrate 100. The grid pattern 130 may also be referred to herein as a“light-impeding pattern,” as it may reflect, block, or otherwise impedeoblique light L1 from passing to a photoelectric conversion region PD.In some embodiments, the grid pattern 130 may be referred to herein as a“light-reflecting pattern” or a “light-blocking pattern” when itreflects or blocks, respectively, oblique light L1. The anti-reflectionlayer 120 may be provided between the substrate 100 and the grid pattern130. The grid pattern 130 may overlap the plurality of pixels PX and thedevice isolation pattern 102, when viewed in a plan view, andhereinafter, the plan view refer to a plane perpendicular to the firstdirection D1. The grid pattern 130 may have a plurality of openings 132,which are provided to penetrate (e.g., to extend completely through) thegrid pattern 130. For example, each of the openings 132 may extendthrough an upper surface and a lower surface of the grid pattern 130.Each of the openings 132 may be provided to expose a top surface of theanti-reflection layer 120. The plurality of openings 132 may be formedon the plurality of pixels PX, respectively, and may be spaced apartfrom each other in a direction parallel to the first surface 100 a ofthe substrate 100. As an example, when viewed in a plan view, theplurality of pixels PX may be two-dimensionally arranged in a seconddirection D2 and a third direction D3, as illustrated in FIG. 2. Thesecond direction D2 and the third direction D3 may be parallel to thefirst surface 100 a of the substrate 100 and may traverse (e.g. cross)each other. The second direction D2 and the third direction D3 may beperpendicular to the first direction D1. In this case, the plurality ofopenings 132 may be spaced apart from each other in both of the secondand third directions D2 and D3 and may be formed on the plurality ofpixels PX, respectively. Each of the openings 132 may be circular, whenviewed in a plan view, but the inventive concepts are not limitedthereto. In some embodiments, each of the openings 132 may be tetragonalor rectangular, when viewed in a plan view.

The plurality of openings 132 may respectively overlap the plurality ofpixels PX when viewed in a plan view. The light L may be incident intothe pixels PX through the openings 132. Each of the openings 132 mayhave a first width 132W that is smaller than a second width PX_W of eachof the pixels PX. The second width PX_W of each of the pixels PX may bea widest width thereof. It will be understood that when each of theplurality of openings 132 is circular, the first width 132W is adiameter thereof, when viewed in a plan view. It will be also understoodthat when each of the plurality of openings 132 is not circular, thefirst width 132W is a widest width thereof. The first width 132W and thesecond width PX_W may be distances measured in a direction parallel tothe first surface 100 a of the substrate 100 (e.g., in the seconddirection D2). As shown in FIG. 3, the second width PX_W may be acenter-to-center distance between a pair of the device isolationpatterns 102 that are located to face each other with each pixel PXinterposed therebetween.

As an example, a ratio of the first width 132W to the second width PX_Wmay be greater than 0 and less than 1 (i.e., 0<132W/PX_W <1). The firstwidth 132W may be selected/adjusted to impede/prevent an oblique lightL1, which is incident at an oblique angle relative to the first surface100 a of the substrate 100, from being incident into the pixels PX andbe selected/adjusted to allow the oblique light L1 to be reflected bythe grid pattern 130. A direct light L2, which is incident at asubstantially right angle relative to the first surface 100 a of thesubstrate 100, may be incident onto/into the pixels PX through theopenings 132. In other words, the first width 132W may beselected/adjusted to allow each of the pixels PX to selectively collecta portion/fraction (i.e., the direct light L2) of the light Lpropagating toward the first surface 100 a of the substrate 100. Here,the direct light L2 may be defined as a portion/fraction of the light Lwith an incident angle of about 0° to about 15°. An incident angle ofthe light L refers to an angle between a direction perpendicular to thefirst surface 100 a of the substrate 100 (e.g., the first direction D1)and the light. If a ratio of the first width 132W to the second widthPX_W decreases, a range of the incident angle of the direct light L2 tobe collected by each of the pixels PX may be decreased. The first width132W may be selected/adjusted to allow each of the pixels PX toselectively collect light to be incident at a desired incident angle.

In some embodiments, an opening 132 may be centered with respect to(i.e., aligned with a center of) a lens 140 and/or a photoelectricconversion region PD, as illustrated in FIG. 2. Accordingly, the directlight L2 may be selectively provided from the lens 140 (e.g., from thecenter thereof) to the photoelectric conversion region PD (e.g., to thecenter thereof).

The grid pattern 130 may have a third width 130W corresponding to adistance (e.g., shortest distance) between an adjacent pair of theopenings 132. Between each adjacent pair of the pixels PX, the deviceisolation pattern 102 may have a fourth width 102W. The fourth width102W may be a distance between side surfaces, which are respectivelyadjacent to each pair of the pixels PX, of the device isolation pattern102. The third width 130W and the fourth width 102W may be distancesthat are measured in a direction parallel to the first surface 100 a ofthe substrate 100 (e.g., in the second direction D2). The third width130W may be larger (i.e., wider) than the fourth width 102W. The gridpattern 130 may be formed of or include a metallic material (e.g., atleast one of metals or metal nitrides).

A planarization layer 150 may be provided on the first surface 100 a ofthe substrate 100. The planarization layer 150 may extend on (e.g.,cover) the grid pattern 130, and the grid pattern 130 may be provided inthe planarization layer 150. The planarization layer 150 may extend on(e.g., cover) the top surface of the grid pattern 130 and may beextended into each of the openings 132 to be in contact with theanti-reflection layer 120. The planarization layer 150 may contain highconcentration of impurities. As an example, the planarization layer 150may contain p-type impurities such as boron (B).

A plurality of micro lenses 140 may be provided on the first surface 100a of the substrate 100. An array/group of the micro lenses 140 may beprovided on the planarization layer 150. In some embodiments, the microlenses 140 may directly contact the planarization layer 150, asillustrated in FIG. 3. The planarization layer 150 may be providedbetween the substrate 100 and an array of the micro lenses 140, and thegrid pattern 130 may be provided between the substrate 100 and theplanarization layer 150. When viewed in a plan view, the micro lenses140 may respectively overlap the pixels PX, and may respectively overlapthe openings 132. Accordingly, each of the openings 132 may beoverlapped by a corresponding one of the micro lenses 140 and mayoverlap a corresponding one of the pixels PX, when viewed in a planview.

Although the term “micro lens” is used herein, it will be understoodthat the micro lens 140 may be one of various types of lenses for animage sensor. Moreover, it will be understood that the grid pattern 130may selectively pass or impede light L based on different locationswhere the grid pattern 130 overlaps a photoelectric conversion region PD(to block/reflect oblique light L1) or has an opening 132 (that passesdirect light L2 to the photoelectric conversion region PD). Accordingly,the grid pattern 130 may be referred to herein as “a light-impedingpattern” that is between a first portion of the lens 140 and a firstportion of the photoelectric conversion region PD (e.g., a portion thatis vertically aligned with the first portion of the lens 140), toblock/reflect oblique light L1. Moreover, the light-impeding pattern 130may include an opening 132 therein between a second portion of the lens140 and a second portion of the photoelectric conversion region PD(e.g., a portion that is vertically aligned with the second portion ofthe lens 140), to pass direct light L2.

The first width 132W of each of the openings 132 may be smaller than adiameter 140D of each of the micro lenses 140. As an example, a ratio ofthe first width 132W to the diameter 140D may be greater than 0 and lessthan 0.7 (i.e., 0<132W/140D <0.7). For example, the ratio of the firstwidth 132W to the diameter 140D may be about 1:10 (i.e., 132W/140D=0.1).The diameter 140D may be a distance measured in a direction parallel tothe first surface 100 a of the substrate 100 (e.g., in the seconddirection D2). The first width 132W of each of the openings 132 may beselected/adjusted to impede/prevent the oblique light L1, which isincident through the micro lenses 140, from being incident onto/into thepixels PX and selected/adjusted to allow the oblique light L1 to bereflected by the grid pattern 130. The direct light L2 to be incidentthrough the micro lenses 140 may be incident onto/into the plurality ofpixels PX through the plurality of openings 132. In other words, thefirst width 132W may be selected/adjusted to allow each of the pixels PXto selectively collect a portion/fraction (i.e., the direct light L2) ofthe light L propagating toward the first surface 100 a of the substrate100. If a ratio of the first width 132W to the diameter 140D decreases,a range of the incident angle of the direct light L2 to be collected byeach of the pixels PX may be decreased.

When viewed in a sectional view, the array of the micro lenses 140 maybe spaced apart from the grid pattern 130 by a first distance 150H. Ineach of the micro lenses 140, the ratio of the first distance 150H tothe diameter 140D may range from about 1:1 to about 1:1.5. A curvatureradius of each of the micro lenses 140 may range from about 2.8 μm to3.0 μm. As an example, the curvature radius of each of the micro lenses140 may be about 2.92 μm.

If a range of an incident angle of light to be collected by each of thepixels PX is relatively large, an image blur phenomenon may occur when anear object is selected as a subject to be imaged. That is, there may bea difficulty in taking an image of a near object.

According to some embodiments of the inventive concepts, each of theopenings 132 of the grid pattern 130 may have a width that is smallerthan a width of each pixel PX and a diameter of each micro lens 140(i.e., PX_W and 140D). The width of each of the openings 132 may beselected/adjusted to allow light L, which is collected by each of thepixels PX, to have a relatively small incident angle range. For example,the ratio of the first width 132W to the diameter 140D may be greaterthan 1:10, greater than 1:9, greater than 1:8, greater than 1:7, greaterthan 1:6, greater than 1:5, greater than 1:4, greater than 1:3, orgreater than 1:2, but less than 0.7 (i.e., first width 132W/diameter140D <0.7). In some embodiments, the ratio of the first width 132W tothe diameter 140D may be at least about 1:2. In some embodiments, theratio of the first width 132W to the diameter 140D may be about 1:10.This may make it possible to realize an image sensor capable of easilytaking an image of a near object. In some embodiments, the image sensormay be used for fingerprint recognition.

FIG. 4 is a sectional view, which is taken along a line corresponding tothe line I-I′ of FIG. 2 and illustrates a modified example of an imagesensor according to some embodiments of the inventive concepts. In thefollowing description, an element previously described with reference toFIGS. 2 and 3 may be identified by a similar or identical referencenumber without repeating an overlapping description thereof, for thesake of brevity.

Referring to FIGS. 2 and 4, color filters CF may be provided on thefirst surface 100 a of the substrate 100. An array (e.g., a group) ofthe color filters CF may be provided between the planarization layer 150and the array of the micro lenses 140. In some embodiments, the microlenses 140 may directly contact the color filters CF. When viewed in aplan view normal (e.g., perpendicular) to the first direction D1, thecolor filters CF may overlap the plurality of pixels PX, respectively,and may overlap the plurality of openings 132, respectively.

Referring to FIGS. 2 and 4, a planarization layer 150 may be provided onthe first surface 100 a of the substrate 100. The planarization layer150 may be provided between the anti-reflection layer 120 and thearray/group of the color filters CF. The grid pattern 130 may beprovided in the planarization layer 150. The planarization layer 150 mayextend on (e.g., cover) a top surface of the grid pattern 130 and mayextend into each of the openings 132 to be in contact with theanti-reflection layer 120. The planarization layer 150 may contain ahigh concentration of impurities. As an example, the planarization layer150 may contain p-type impurities such as boron (B).

FIG. 5 is a sectional view, which is taken along a line corresponding tothe line I-P of FIG. 2 and illustrates another modified example of animage sensor according to some embodiments of the inventive concepts. Inthe following description, an element previously described withreference to FIGS. 2 and 3 may be identified by a similar or identicalreference number without repeating an overlapping description thereof,for the sake of brevity.

Referring to FIGS. 2 and 5, the photoelectric conversion region PD andthe well region 104 may be provided in each of the pixels PX. The wellregion 104 may be provided adjacent to the first surface 100 a of thesubstrate 100, and the photoelectric conversion region PD may be spacedapart from the first surface 100 a of the substrate 100 with the wellregion 104 interposed therebetween. The floating diffusion region FD maybe provided in each of the pixels PX. The floating diffusion region FDmay be provided in the well region 104 to be adjacent to the firstsurface 100 a of the substrate 100. The transfer gates TG may beprovided on the first surface 100 a of the substrate 100.

The interconnection structure 110 may be provided on the first surface100 a of the substrate 100. The interconnection structure 110 may beprovided between the substrate 100 and the anti-reflection layer 120.The interconnection structure 110 may include the first interlayerinsulating layer 110 a, the second interlayer insulating layer 110 b,and the third interlayer insulating layer 110 c, which are sequentiallystacked on the first surface 100 a of the substrate 100. The firstinterlayer insulating layer 110 a may be provided to be in contact withthe first surface 100 a of the substrate 100 and may extend on (e.g.,cover) the transfer gates TG. The third interlayer insulating layer 110c may be in contact with the anti-reflection layer 120.

Although FIGS. 3 and 5 do not show color filters CF, it will beunderstood that color filters CF can be provided between the microlenses 140 and the planarization layer 150. In some embodiments, themicro lenses 140 of FIGS. 3 and 5 may directly contact underlying thecolor filters CF.

FIG. 6 is a plan view of an image sensor according to some embodimentsof the inventive concepts, and FIG. 7 is a sectional view taken alongthe line I-I′ of FIG. 6. In the following description, an elementpreviously described with reference to FIGS. 2 and 3 may be identifiedby a similar or identical reference number without repeating anoverlapping description thereof, for the sake of brevity.

Referring to FIGS. 6 and 7, the micro lenses 140 may be provided on thefirst surface 100 a of the substrate 100. The micro lenses 140 mayrespectively overlap the pixels PX when viewed in a plan view. The gridpattern 130 may be provided between the substrate 100 and thearray/group of the micro lenses 140, and when viewed in a plan view,each of the openings 132 may be overlapped by a corresponding one of themicro lenses 140 and may overlap a corresponding one of the plurality ofpixels PX. The first width 132W of each of the openings 132 may be lessthan the second width PX_W of each of the pixels PX and may be less thanthe diameter 140D of each of the micro lenses 140.

According to some embodiments, as illustrated in FIG. 7, the diameter140D of each of the micro lenses 140 may be less (i.e., narrower) thanthe second width PX_W of each of the pixels PX. If a size of each of themicro lenses 140 is reduced, an amount of light to be collected by eachof the micro lenses 140 may be reduced. According to some embodiments,however, as illustrated in FIG. 7, a curvature of each of the microlenses 140 may increase as the diameter 140D of each of the micro lenses140 decreases. Accordingly, it may be possible to prevent or suppress anamount of light collected by the micro lenses 140 from being decreased.In other words, the curvature of each of the micro lenses 140 may beselected/adjusted to compensate for the decrease in the amount of lightto be collected by each of the micro lenses 140. Furthermore, if thecurvature of each of the micro lenses 140 is increased, a ratio of theoblique light L1 to the light L may be increased. In this case, thefirst width 132W of each of the openings 132 may be more easilyselected/adjusted to be within a range in which the oblique light L1 isimpeded/prevented from being incident onto/into unintended ones of thepixels PX and is allowed to be reflected by the grid pattern 130. Thus,each of the pixels PX may be used to easily and selectively collect thedirect light L2.

The micro lens 140 may have a thickest thickness 140T in the firstdirection D1, and, in some embodiments, the thickest thickness 140T ofthe micro lens 140 may be greater than a radius of the micro lens 140(i.e., half of the diameter 140D).

Each of the micro lenses 140 may be locally provided on thephotoelectric conversion region PD of a corresponding one of the pixelsPX. The micro lenses 140 may be connected to each other by a flatportion 142 interposed therebetween. The flat portion 142 may overlapthe device isolation pattern 102, when viewed in a plan view. The flatportion 142 may have a fifth width 142W corresponding to a distancebetween curved portions of an adjacent pair of the micro lenses 140. Thefifth width 142W may be a distance that is measured in a directionparallel to the first surface 100 a of the substrate 100 (e.g., in thesecond direction D2). The fifth width 142W may be a shortest distancebetween the curved portions of an adjacent pair of the micro lenses 140,as illustrated in FIG. 6. The fifth width 142W of the flat portion 142may be smaller (i.e., narrower) than the third width 130W of the gridpattern 130 and may be larger (i.e., wider) than the fourth width 102Wof the device isolation pattern 102.

In some embodiments, the diameter 140D of each of the micro lenses 140may be narrower than a sixth width PD _W of each of the photoelectricconversion regions PD, as illustrated in FIGS. 6 and 7. Accordingly,each of the photoelectric conversion regions PD may include an edgeportion that is not overlapped by a corresponding one of the microlenses 140, when viewed in a plan view. The diameter 140D may be adistance that is measured in a direction parallel to the first surface100 a of the substrate 100 (e.g., in the second direction D2). It willbe understood that when each of the micro lenses 140 is not circular,the diameter 140D may be a widest width of each of the micro lenses 140,which is measured in a direction parallel to the first surface 100 a ofthe substrate 100 (e.g., in the second direction D2).

FIG. 8 is a plan view of an image sensor according to some embodimentsof the inventive concepts, and FIG. 9 is a sectional view taken alongthe line I-I′ of FIG. 8. In the following description, an elementpreviously described with reference to FIGS. 2 and 3 may be identifiedby a similar or identical reference number without repeating anoverlapping description thereof, for the sake of brevity.

Referring to FIGS. 8 and 9, the grid pattern 130 may be provided on thefirst surface 100 a of the substrate 100. The anti-reflection layer 120may be provided between the substrate 100 and the grid pattern 130. Thegrid pattern 130 may overlap the plurality of pixels PX and the deviceisolation pattern 102 when viewed in a plan view. The grid pattern 130may have the plurality of openings 132, which are provided to penetrate(e.g., completely extend through) the grid pattern 130. Each of theopenings 132 may be provided to expose a top surface of theanti-reflection layer 120. The plurality of openings 132 may be spacedapart from each other in a direction parallel to the first surface 100 aof the substrate 100. According to some embodiments, as illustrated inFIG. 9, more than one of the openings 132 may overlap acommon/single/same one of the plurality of pixels PX, when viewed in aplan view. As an example, at least two openings 132 may be provided oneach of the pixels PX. Accordingly, at least two openings 132 mayoverlap a common (i.e., same) one of the pixels PX. Although FIG. 8illustrates the grid pattern 130 which is formed to have four openings132 on each of the pixels PX, the inventive concepts are not limitedthereto. For example, the number of the openings 132 provided on each ofthe pixels PX may be variously selected/changed. The first width 132W ofeach of the openings 132 may be smaller (i.e., narrower) than the secondwidth PX_W of each of the pixels PX.

The micro lenses 140 may be provided on the first surface 100 a of thesubstrate 100. The grid pattern 130 may be provided between thesubstrate 100 and the array/group of the micro lenses 140, and whenviewed in a plan view, the openings 132 may be respectively overlappedby the micro lenses 140. According to some embodiments, as illustratedin FIG. 9, more than one of the micro lenses 140 may respectivelyoverlap a common/single/same one of the pixels PX when viewed in a planview. As an example, at least two micro lenses 140 may be provided oneach of the pixels PX. Although FIG. 8 illustrates a structure includingfour micro lenses 140 on each of the pixels PX, the inventive conceptsare not limited thereto. For example, the number of the micro lenses 140provided on each of the pixels PX may be variously selected/changed. Thefirst width 132W of each of the openings 132 may be smaller (i.e.,narrower) than the diameter 140D of each of the micro lenses 140. Thediameter 140D of each of the micro lenses 140 may be smaller (i.e.,narrower) than the second width PX_W of each of the pixels PX. As thediameter 140D decreases, the curvature of each of the micro lenses 140may increase. According to some embodiments, each of the pixels PX maybe used to easily and selectively collect the direct light L2.

FIG. 10 is a plan view of an image sensor according to some embodimentsof the inventive concepts, and FIG. 11 is a sectional view taken alongthe line I-I′ of FIG. 10. In the following description, an elementpreviously described with reference to FIGS. 2 and 3 may be identifiedby a similar or identical reference number without repeating anoverlapping description thereof, for the sake of brevity.

Referring to FIGS. 10 and 11, the grid pattern 130 may be provided onthe first surface 100 a of the substrate 100. The anti-reflection layer120 may be provided between the substrate 100 and the grid pattern 130.The grid pattern 130 may overlap the plurality of pixels PX and thedevice isolation pattern 102, when viewed in a plan view. The gridpattern 130 may have the plurality of openings 132, which are providedto penetrate the grid pattern 130. Each of the openings 132 may beprovided to expose a top surface of the anti-reflection layer 120.According to some embodiments, each of the openings 132 may overlap acorresponding one of the plurality of pixels PX, when viewed in a planview. The grid pattern 130 may extend onto neighboring pixels PX, whichare located directly adjacent to the corresponding one of the pixels PXthat is overlapped by an opening 132, and the grid pattern 130 may coverrespective portions of the neighboring pixels PX. That is, the opening132 of the grid pattern 130 may be formed to impede/prevent the light Lfrom being incident into the neighboring pixels PX that are locateddirectly adjacent thereto. The first width 132W of each of the openings132 may be smaller (i.e., narrower) than the second width PX_W of eachof the pixels PX. In some embodiments, the grid pattern 130 may entirelycovers upper surfaces of photoelectric conversion regions PD of theneighboring pixels PX, as illustrated in FIG. 10. Referring to FIG. 10,in some embodiments, no openings 132 of the grid pattern 130 may overlapthe photoelectric conversion regions PD of the neighboring pixels PX.

The micro lenses 140 may be provided on the first surface 100 a of thesubstrate 100. The grid pattern 130 may be provided between thesubstrate 100 and the array/group of the micro lenses 140. The openings132 may be respectively overlapped by the micro lenses 140 when viewedin a plan view. According to some embodiments, each of the micro lenses140 may respectively overlap a corresponding one of the pixels PX, whenviewed in a plan view. Each of the micro lenses 140 may extend ontoneighboring pixels PX, which are located directly adjacent to thecorresponding one of the pixels PX that is overlapped by an opening 132.The first width 132W of each of the openings 132 may be smaller (i.e.,narrower) than the diameter 140D of each of the micro lenses 140. Thediameter 140D of each of the micro lenses 140 may be larger (i.e.,wider) than the second width PX_W of each of the pixels PX. In thiscase, as the size of the micro lenses 140 increases, an amount of lightto be collected by the micro lenses 140 may be increased.

FIGS. 12A and 12B are graphs, each of which shows an angular response ofan image sensor according to some embodiments of the inventive concepts.

Referring to FIG. 12A, an image sensor according to some embodiments ofthe inventive concepts may generate signal in response to an obliquelight to be incident at an incident angle of about 15° or greater, whichhas magnitude(i.e. a ratio of output signal to input signal) that isless than 50% of magnitude of signal generated in response to a directlight (e.g., light having an incident angle of 0°) to be incident in adirection normal (e.g., perpendicular) to the first surface 100 a. Itwill be understood that a grid pattern 130 of the image sensor mayimpede/prevent more than 50% of an oblique light with an incident angleof about 15° or greater from being incident into pixels PX of the imagesensor. This may be achieved when each of the openings 132 of the gridpattern 130 have a desired (e.g., predetermined) width that is smallerthan a width of each of the pixels PX and a diameter of each of themicro lenses 140. It will be also understood that magnitude of signalgenerated by a pixel of an image sensor may be proportional to thenumber electrical charges (e.g., electrons) generated by the pixel ofthe image sensor.

Referring to FIG. 12B, an image sensor according to some embodiments ofthe inventive concepts may generate signal in response to an obliquelight to be incident at an incident angle of about 2.5° or greater,which has magnitude that is less than 50% of magnitude of signalgenerated in response to a direct light (e.g., light having an incidentangle of 0°) to be incident in a direction normal to the first surface100 a. It will be understood that a grid pattern 130 of the image sensormay impede/prevent more than 50% of an oblique light with an incidentangle of about 2.5° or greater from being incident into pixels PX of theimage sensor. This may be achieved when a ratio of the first width 132Wof the opening 132 of the grid pattern 130 to the diameter 140D of themicro lens 140 is about 1:10, a ratio of the first distance 150H to thediameter 140D of the micro lens 140 ranges from about 1:1 to about1:1.5, and a curvature radius of the micro lens 140 is about 2.92 μm.

FIGS. 13A and 13B are sectional views, each of which illustrates theportion A of FIG. 3. Hereinafter, the anti-reflection layer 120 of animage sensor according to some embodiments of the inventive conceptswill be described in more detail.

Referring to FIG. 13A, the anti-reflection layer 120 according to someembodiments of the inventive concepts may be provided to extend on(e.g., cover) the top surface of the device isolation pattern 102, andthe device isolation pattern 102 may be formed of or include at leastone of oxide, nitride, and oxynitride. The device isolation pattern 102may include oxide, nitride, and/or oxynitride. The anti-reflection layer120 may be a multi-layered structure including a plurality of layerssequentially stacked on the first surface 100 a of the substrate 100.For example, the anti-reflection layer 120 may include a first oxide121, a second oxide 123, a third oxide 125, a fourth oxide 127, and afifth oxide 129, which are sequentially stacked on the first surface 100a of the substrate 100. In some embodiments, the first oxide 121 and thefifth oxide 129 may be formed of or include the same material. As anexample, the first oxide 121 and the fifth oxide 129 may be formed of orinclude aluminum oxide. In some embodiments, the second oxide 123 andthe fourth oxide 127 may be formed of or include the same material. Asan example, the second oxide 123 and the fourth oxide 127 may be formedof or include hafnium oxide. The third oxide 125 may be formed of orinclude, for example, silicon oxide. The third oxide 125 may be thickerthan other oxides 121, 123, 127, and 129.

Referring to FIG. 13B, the anti-reflection layer 120 according to someembodiments of the inventive concepts may be a multi-layered structureincluding a plurality of layers, which are sequentially stacked on thefirst surface 100 a of the substrate 100. For example, theanti-reflection layer 120 may include the first oxide 121, the secondoxide 123, the third oxide 125, the fourth oxide 127, and the fifthoxide 129, which are sequentially stacked on the first surface 100 a ofthe substrate 100. In some embodiments, at least a portion of theanti-reflection layer 120 (e.g., at least a portion of the first tofifth oxides 121, 123, 125, 127, and 129) may be extended into a trench102T that penetrates the substrate 100. The at least portion of theanti-reflection layer 120 may be the device isolation pattern 102.

FIGS. 14A to 14C are sectional views, which are taken along a linecorresponding to the line I-I′ of FIG. 2 to illustrate a method offorming a grid pattern of an image sensor according to some embodimentsof the inventive concepts. In order to reduce complexity in thedrawings, detailed illustrations of the substrate 100, theinterconnection structure 110, and the anti-reflection layer 120 areomitted from FIGS. 14A to 14C.

Referring to FIG. 14A, a metal layer 134 and a mask layer 160 may besequentially formed on a lower structure 200. The lower structure 200may be a structure, in which the substrate 100, the interconnectionstructure 110, and the anti-reflection layer 120 described withreference to FIGS. 3 to 5 are provided. The lower structure 200 mayinclude elements (e.g., the photoelectric conversion region PD, theinterconnection lines 114, and so forth), which are provided in thesubstrate 100 and the interconnection structure 110. The metal layer 134may be formed of or include at least one of metals and metal nitrides.The metal layer 134 may include metal and/or metal nitride. The masklayer 160 may be a hard mask layer which is formed of or includes atleast one of oxide, nitride, and oxynitride. The mask layer 160 mayinclude oxide, nitride, and/or oxynitride.

A photoresist pattern 170 may be formed on the mask layer 160. Thephotoresist pattern 170 may be used to form the grid pattern 130described with reference to FIGS. 3 to 5. The photoresist pattern 170may include a plurality of first holes 172, which are formed topenetrate the photoresist pattern 170 and to expose a top surface of themask layer 160. Each of the first holes 172 may define a shape and aposition of a corresponding one of the openings 132 which will be formedin the grid pattern 130.

Referring to FIG. 14B, the mask layer 160 may be etched using thephotoresist pattern 170 as an etch mask to form a mask pattern 162. Asan example, the etching of the mask layer 160 may be performed using adry etching process. The photoresist pattern 170 may be removed using anashing and/or strip process. The mask pattern 162 may include aplurality of second holes 164, which are formed to penetrate the maskpattern 162 and to expose a top surface of the metal layer 134. Each ofthe second holes 164 may be used to define a position and a shape of acorresponding one of the openings 132, which will be formed in the metallayer 134.

Referring to FIG. 14C, the metal layer 134 may be etched using the maskpattern 162 as an etch mask to form the grid pattern 130. As an example,the etching of the metal layer 134 may be performed using a dry etchingprocess. The mask pattern 162 may be removed using, for example, a stripprocess. The grid pattern 130 may include the plurality of openings 132,which are formed to penetrate the grid pattern 130 and to expose a topsurface of the lower structure 200. As described with reference to FIGS.3 to 5, each of the openings 132 may be formed to have a desired (e.g.,predetermined) width 132W.

The grid pattern 130 described with reference to FIGS. 6 to 11 may beformed by substantially the same or similar method.

FIGS. 15A and 15B are sectional views, which are taken along a linecorresponding to the line I-I′ of FIG. 2 to illustrate a method offabricating an image sensor according to some embodiments of theinventive concepts.

Referring to FIG. 15A, the device isolation pattern 102 may be formed inthe substrate 100. The formation of the device isolation pattern 102 mayinclude forming the trench 102T to penetrate at least a portion of thesubstrate 100 and forming an insulating layer to fill the trench 102T.The photoelectric conversion region PD and the well region 104 may beformed in the substrate 100. The photoelectric conversion region PD maybe formed by doping a portion of the substrate 100 with the firstconductivity type impurities, and the well region 104 may be formed bydoping another portion of the substrate 100 with the second conductivitytype impurities. In addition, the floating diffusion region FD and thetransfer gates TG adjacent thereto may be formed in the substrate 100.The floating diffusion region FD may be formed by doping other region ofthe substrate 100 with the first conductivity type impurities.

The interconnection structure 110 may be formed on the second surface100 b of the substrate 100. The formation of the interconnectionstructure 110 may include forming the first interlayered insulatinglayer 110 a on the second surface 100 b of the substrate 100 to extendon (e.g., cover) the transfer gates TG, forming the vias 112 topenetrate the first interlayered insulating layer 110 a, forming theinterconnection lines 114 on the first interlayered insulating layer 110a to connect the vias 112 to each other, and forming the second andthird interlayered insulating layers 110 b and 110 c to extend on (e.g.,cover) the interconnection lines 114. In some embodiments, after theformation of the interconnection structure 110, a back-grinding processmay be performed on the first surface 100 a of the substrate 100. Theback-grinding process may be performed to expose the device isolationpattern 102 through the first surface 100 a of the substrate 100.Thereafter, the anti-reflection layer 120 may be formed on the firstsurface 100 a of the substrate 100.

As an example, as shown in FIG. 13A, the anti-reflection layer 120 maybe a multi-layered structure including a plurality of layerssequentially stacked on the first surface 100 a of the substrate 100. Asan example, as shown in FIG. 13B, at least a portion of theanti-reflection layer 120 (i.e., at least a portion of the first tofifth oxides 121, 123, 125, 127, and 129) may be formed to extend on(e.g., cover) an inner surface of the trench 102T, and in this case, theat least portion of the anti-reflection layer 120 may be at least aportion of the device isolation pattern 102.

Referring to FIG. 15B, the grid pattern 130 may be formed on theanti-reflection layer 120. The grid pattern 130 may be formed by themethod described with reference to FIGS. 14A to 14B.

Referring back to FIG. 3, the planarization layer 150 and thearray/group of the micro lenses 140 may be sequentially formed on thegrid pattern 130.

FIG. 16 is a schematic diagram of an electronic device including animage sensor according to some embodiments of the inventive concepts.FIG. 17 is a sectional view taken along the line I-I′ of FIG. 16illustrating structure and operation of the image sensor.

Referring to FIGS. 16 and 17, an image sensor according to someembodiments of the inventive concepts may be used as a part of anelectronic device 2000 (e.g., a mobile phone or a smart phone) with animaging function. The electronic device 2000 may include a printedcircuit board 1000, a display panel 1500 provided on the printed circuitboard 1000, and a sensing unit 1600 between the printed circuit board1000 and the display panel 1500. The display panel 1500 may include alight source 1510 (e.g., OLED) provided therein. The sensing unit 1600may be electrically connected to the printed circuit board 1000 throughconductive elements 1400. The sensing unit 1600 may include afingerprint sensor 1100, which is provided on a package substrate 1300,and a protection layer 1200, which is provided on the package substrate1300 to extend on (e.g., cover) the fingerprint sensor 1100. The sensingunit 1600 may be referred to as an optical scanner, and the fingerprintsensor 1100 may be referred to as an optical sensor.

Referring to FIG. 17, when a finger 3000 touches a surface of a portionof the display panel 1500, light may be emitted from the light source1510 of the display panel 1500 and may be reflected off the finger 3000,and the fingerprint sensor 1100 may sense the reflected light 1700. Insome embodiments, the reflected light 1700 may travel through thedisplay panel 1500 (e.g., the light source 1510 of the display panel1500) as illustrated in FIG. 17. The image sensors according to someembodiments of the inventive concepts may be used as the fingerprintsensor 1100. In this case, the image sensors may be configured toselectively collect a direct light to be incident into the sensor 1100in a substantially perpendicular direction. This may make it possible toeasy recognize the fingerprint. In some embodiments, no additional lens(e.g., module lens) may be provided between the light source 1510 of thedisplay panel 1500 and the fingerprint sensor 1100 that includes microlenses therein. In some embodiments, no additional lens (e.g., modulelens) may be provided between a surface of a portion of the displaypanel 1500, which a finger contacts, and the fingerprint sensor 1100that includes micro lenses therein.

It will be understood that when the fingerprint sensor 1100 is assembledwith the display panel 1500, the first surface 100 a of the substrate100 of FIGS. 3, 4, 5, 7, 9, and 11 faces the display panel 1500, andthus the micro lenses 140 are provided between the display panel 1500and the grid pattern 130.

It will be understood that the portion of the display panel 1500overlapping the fingerprint sensor 1100 and a remaining portion of thedisplay panel 1500 may include the same elements, and thus the portionof the display panel 1500 may be also used to display images when thisportion is not used as a scanner. Accordingly, the display panel 1500may not include a portion that is dedicated only for scanning.

According to some embodiments of the inventive concepts, a grid patternmay have a plurality of openings, each of which penetrates (e.g.,completely extend through) the grid pattern, vertically overlaps acorresponding one of pixels, and is vertically overlapped by acorresponding one of micro lenses. Each of the openings may have a widththat is smaller (i.e., narrower) than a width of the corresponding pixeland a diameter of the corresponding micro lens, and thus, thecorresponding pixel may be used to selectively collect light to beincident at a desired (e.g., predetermined) incident angle. This maymake it possible to realize an image sensor capable of easily reducingimage blur when taking an image of a near object (e.g., finger), asreducing the range of incident angles of light collected by the pixelsmay reduce image blur.

According to some embodiments of the inventive concepts, the width ofeach of the openings in the grid pattern may be selected/adjusted toallow the corresponding pixel to selectively collect light to beincident at a desired incident angle. Thus, in an image sensor accordingto some embodiments of the inventive concepts, it may be possible toselectively collect light to be incident at the desired incident angleand to easily reduce image blur when taking an image of a near object.

The above-disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments, which fall withinthe true spirit and scope of the inventive concepts. Thus, to themaximum extent allowed by law, the scope is to be determined by thebroadest permissible interpretation of the following claims and theirequivalents, and shall not be restricted or limited by the foregoingdetailed description.

What is claimed is:
 1. An electronic device comprising: an organic lightemitting diode(OLED); and an optical sensor comprising: a substrate; afirst micro-lens; a second micro-lens; a first opening between a firstphotodiode in the substrate and the first micro-lens; a second openingbetween a second photodiode in the substrate and the second micro-lens;and a device isolation pattern between the first photodiode and thesecond photodiode, wherein a width of the first opening is smaller thana distance between the first opening and the second opening, and whereinthe optical sensor is configured to be assembled with the OLED such thatthe first micro-lens is disposed between the first opening and the OLED.2. The electronic device of claim 1, wherein the first opening iscircular in a plan view.
 3. The electronic device of claim 2 furthercomprising a grid pattern, wherein the grid pattern includes a metallicmaterial.
 4. The electronic device of claim 3, wherein the substrate hasa first surface and a second surface, and wherein the device isolationpattern has a top surface that is coplanar with the first surface and abottom surface that is coplanar with the second surface.
 5. Theelectronic device of claim 3, wherein the substrate has a first surfaceand a second surface, and wherein the device isolation pattern has a topsurface that is coplanar with the first surface and a bottom surfacethat is adjacent to the second surface.
 6. The electronic device ofclaim 5, wherein the optical sensor is configured to senses a reflectedlight from a finger through the OLED.
 7. The electronic device of claim6 further comprising a color filter between the first micro-lens and thefirst opening.
 8. The electronic device of claim 6, wherein theelectronic device is a mobile phone.
 9. The electronic device of claim6, a width of the device isolation pattern is smaller than the width ofthe first opening.
 10. The electronic device of claim 1, wherein thefirst opening is rectangular in a plan view.
 11. An electronic devicecomprising: an organic light emitting diode(OLED); and an optical sensorcomprising: a substrate including a first photodiode and a secondphotodiode; a device isolation pattern between the first photodiode andthe second photodiode; an opening on the first photodiode; and amicro-lens overlapping the first photodiode and the second photodiode,wherein the optical sensor is configured to be assembled with the OLEDsuch that the micro-lens is disposed between the opening and the OLED.12. The electronic device of claim 11, wherein a diameter of themicro-lens is larger than a width of the first photodiode.
 13. Theelectronic device of claim 12 further comprising a planarization layerbetween the opening and the micro-lens.
 14. An electronic devicecomprising: a display panel; and an optical sensor comprising: asubstrate; a grid pattern on the substrate; a first photodiode in thesubstrate; a second photodiode in the substrate; a first opening in thegrid pattern, the first opening overlapping the first photodiode; asecond opening in the grid pattern, the second opening overlapping thesecond photodiode; and a device isolation pattern between the firstphotodiode and the second photodiode, wherein a width of the firstopening is smaller than a distance between the first opening and thesecond opening, and wherein the optical sensor is configured to beassembled with the display panel such that the grid pattern is disposedbetween the first photodiode and the display panel.
 15. The electronicdevice of claim 14, wherein the display panel includes a light source.16. The electronic device of claim 15, wherein a width of the deviceisolation pattern is smaller than the width of the first opening. 17.The electronic device of claim 16, wherein the electronic device is amobile phone.
 18. The electronic device of claim 17, wherein the lightsource is an organic light emitting diode.
 19. The electronic device ofclaim 18 further comprising a micro-lens between the display panel andthe grid pattern.
 20. The electronic device of claim 19, wherein acurvature radius of the micro-lens is in a range of from 2.8 μm to 3.0μm.